Passive electrical article

Abstract

A passive electrical article including a dielectric layer having a nonwoven material.

What is claimed is: 
     
       1. A method of making an electrical article comprising:
 providing two conductive substrates, 
 coating a resin on a surface of each conductive substrate, 
 providing an etched nonwoven material between the resin-coated surfaces of the conductive substrates, the etched nonwoven material having a desired areal density, and 
 laminating the resin-coated conductive substrates and the etched nonwoven material together, 
 wherein the providing an etched nonwoven material step comprises providing a first nonwoven material having a first areal density larger than the desired areal density and etching the first nonwoven material to produce the etched nonwoven material, the desired areal density being 20 percent to about 50 percent lower than the first areal density. 
 
     
     
       2. The method of  claim 1  wherein the first nonwoven material is selected from the group consisting of liquid crystal polymer, nylon, polyester, polystyrene, polyacrylonitrile, polypropylene, polyvinylidene fluoride (PVDF),and hybrid materials such as poly(ether sulfone)-polyvinylidene fluoride (PES-PVDF), polyetherimide- polyvinylidene fluoride (PEI-PVDF), polyacrylonitrile- polyvinylidene fluoride (PAN-PVDF), ethylene chlorotrifluoroethylene (ECTFE), and combinations thereof. 
     
     
       3. The method of  claim 1  wherein the etched nonwoven material is about 20 micrometers to about 0.5 micrometers thick. 
     
     
       4. The method of  claim 1  wherein the etched nonwoven material comprises fibers having diameters of about 20 to about 500 nanometers. 
     
     
       5. The method of  claim 1  wherein the first nonwoven material is crosslinked. 
     
     
       6. The method of  claim 1 , wherein etching the first nonwoven material to produce the etched nonwoven material comprises etching the first nonwoven material in an aqueous etching solution comprising an alkali metal salt and an alkanolamine solubilizer. 
     
     
       7. The method of  claim 6 , wherein the first nonwoven material comprises a polyimide copolymer comprising carboxylic ester units in a polymeric backbone of the polyimide copolymer. 
     
     
       8. The method of  claim 1 , wherein etching the first nonwoven material to produce the etched nonwoven material comprises plasma etching with an oxygen and C 3 F 8  plasma. 
     
     
       9. A method of making an electrical article comprising:
 coating a resin layer on a surface of a first conductive substrate, 
 forming an etched nonwoven material on a surface of a second conductive substrate, the etched nonwoven material having a desired areal density, and 
 laminating the conductive substrates together with the resin layer and the etched nonwoven material facing each other, 
 wherein the forming an etched nonwoven material step comprises providing a first nonwoven material having a first areal density larger than the desired areal density and etching the first nonwoven material to produce the etched nonwoven material, the desired areal density being 20 percent to about 50 percent lower than the first areal density. 
 
     
     
       10. The method of  claim 9  wherein the etched nonwoven material is about 20 micrometers to about 0.5 micrometers thick. 
     
     
       11. The method of  claim 9  wherein the etched nonwoven material comprises fibers having diameters of about 20 to about 500 nanometers. 
     
     
       12. A method of making an electrical article comprising:
 forming an etched nonwoven material on a first surface of one or both of a first and second conductive substrate, the etched nonwoven material having a desired areal density; 
 coating a resin layer on the first surfaces of both conductive substrates, and 
 laminating the conductive substrates together with the resin-coated first surfaces facing each other, 
 wherein the forming an etched nonwoven material step comprises providing a first nonwoven material having a first areal density larger than the desired areal density and etching the first nonwoven material to produce the etched nonwoven material, the desired areal density being 20 percent to about 50 percent lower than the first areal density. 
 
     
     
       13. The method of  claim 12  wherein the etched nonwoven material is about 20 micrometers to about 0.5 micrometers thick. 
     
     
       14. The method of  claim 12  wherein the etched nonwoven material comprises fibers having diameters of about 20 to about 500 nanometers.